1. Field of the Invention
The present invention relates to a movement detection system, a movement detection device, a movement detection method and a computer program.
2. Description of the Related Art
In recent years, information processing devices including personal computers (PCs) and personal digital assistants (PDAs) are commonly equipped as standard with wireless network technologies conforming to the IEEE (Institute of Electrical and Electronics Engineers, Inc.) 802.11 series of standards. There is also increasing demand for the development of systems that detect the movement speed or the spatial movement of information processing devices functioning as wireless terminals.
To fulfill the above-mentioned demand, methods have been suggested in which a short-range wireless technology near field communication (NFC) technology, is embedded in the wireless terminal. NFC technology offers a speed of around 100 to 400 kbps and was developed for use in intercommunication with a NFC-compatible device in a close vicinity of approximately 10 cm. If the NFC technology is embedded in a wireless terminal, and the wireless terminal is moved closer to a specified object, the specified object detects the approaching motion of the wireless terminal, and a system can be realized in which processing operations set up in advance can be performed. However, embedding the above-mentioned wireless network technology and the NFC technology in the same information processing device leads to increased complexity of the device structure and an increase in manufacturing costs.
Methods have also been suggested where wireless network technology conforming to IEEE802.11 standards is not used merely for transmitting and receiving information, but also to detect spatial movement of a wireless terminal. A system that measures the strength of a signal output by a wireless terminal and determines the movement speed of that wireless terminal based on changes in the signal strength is disclosed, for example, in Japanese Patent Application Publication No. JP-2006-39762. Alternatively, a system that measures the strength of a beacon signal output by a wireless device and detects spatial movement of the wireless device based on changes in the signal strength is disclosed, for example, in US Patent No. 2005/0221829 [U.S. Pat. No. 7,209,751 B2].